Hitherto, for a silver halide photographic light-sensitive material, a wet development method has been applied using a developing solution after photographing. However, the method has the following inconveniences, and improvement has been desired.
[1] Because development, bleaching, fixing, and drying are carried out, a long time is required for the development processing.
[2] Because plural tanks containing a developing solution are required, a processor cannot be made small in size and light in weight.
[3] Inconveniences, such as the replenishment of a developing solution, the disposal of processing liquids, washing of developing tanks, etc., are required.
In order to improve the above, photographic light-sensitive materials that are processed using a development method by heating (referred to as "heat development" in some cases hereinafter) to a temperature of from 80 to 150.degree. C. are proposed, as described in, for example, the specification of U.S. Pat. No. 3,152,904, the specification of U.S. Pat. No. 3,457,075, JP-B-43-4921 ("JP-B" means an examined Japanese patent publication), and JP-B-43-4924. One example is a method of previously incorporating a precursor for a developing agent in a light-sensitive layer, decomposing the precursor by heating, to form a developing agent, and subjecting to development. In such a heat-development system, the development processing may be carried out by only applying heat, whereby the processing can be carried out in a short time and a processor can be small in size. Furthermore, the system has such characteristics that there are no inconveniences with the replenishment and the disposal of a developing solution.
However, when the light-sensitive material of this system was used as a printing light-sensitive material, distortion of an image and color discrepancy for 4 color plate images (blue, green, red, and black) were caused by the dimensional changes that occurred during heat development. To solve the problem, a method of heat treatment of a support under a low tension is proposed in JP-A-8-211547 ("JP-A" means unexamined published Japanese patent application).
However, in this method, when a heat-developable light-sensitive material after heat development is used for exposure being contacted on a printing plate (e.g., presensitized printing plate (hereinbelow referred to as PS printing plate)), it results in a so-called "printing blur (unsharp)" on the printing plate. Therefore, improvement on this problem has been demanded. The blur occurs due to unfocused photographing at a portion where the planar property of the heat-developed light-sensitive material is deteriorated, so that the plane thereof locally rises up. In particular, this problem is apt to occur at the outer peripheral portion, and it occurs remarkably in a large-sized plate for use in a newspaper, having a side of 45 cm or more.